Polymeric prosthetic socket liners are widely used as an interface between the surface of a residual limb and a prosthetic socket that grasps the residual limb and provides continuity of function between the residual limb and more distal prosthetic components. These socket liners provide padding or pressure distribution surfaces that create greater comfort for the patient, and they also participate in suspension of the prosthetic socket on the residual limb. Suspension usually relies both on the tenacity with which the liner maintains its grasp on the residual limb and on the tenacity with which the socket maintains its grasp on the liner. Satisfactory performance of the prosthesis as a whole depends on many factors, but the quality of the fit of the socket on the residual limb, an optimal liner solution, and the overall quality of suspension of the socket are all very important.
Polymeric prosthetic liners typically include materials such as silicone, urethane, and thermoplastic elastomer gels in the form of blends and block copolymers, as well as mineral oils. These liners are conformable and, when appropriately sized, comfortable and easily donned and removed. Liners fit closely against the skin, and may further be subjected to internal vacuum pressure that ensures a close fit, and if the fit creates an effective seal, may create a subatmospheric pressure internal to the liner. These features contribute to the liner's role in suspension of the prosthetic socket, but they also create a closed environment that supports the buildup of body-generated moisture and heat around the residual limb. Excess heat and moisture are detrimental to the health of the residual limb, as they are damaging to skin integrity and ideal for bacterial colonization.
Although various attempts have been made to remove moisture from prosthetic liners, it has been challenging to remove moisture while still providing adequate suspension force. Thus, improved prosthetic socket liners with moisture management features are still desired.